1953 JEEP DJ engine

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

Dl

12713

FIG.
Dl-11—MEASURING
TELESCOPE GAUGE
1—
Telescope
Gauge
2—
Micrometer

may
be measured with an inside micrometer or
by setting the cylinder
gauge
dial
at zero and meas­
uring
across the
gauge
contact points with an out­side micrometer while the
gauge
is at same zero
setting. Refer to
Figs.
Dl-10 and Dl-11.

b.
If a cylinder bore is moderately rough or slightly

scored,
but is not out-of-round or tapered, it is

usually
possible to remedy the situation by honing
the bore to fit a standard service piston, since
standard
service pistons are high-limit production
pistons. If cylinder bore is very rough or deeply
scored,
it may be necessary to rebore the cylinder
to fit an oversize piston in order to ensure satisfac­
tory
results.

c.
If cylinder bore is tapered .005" [0,127 mm.]

or
more or is out-of-round .003" [0,076 mm.] or

more,
it is advisable to rebore for the smallest possible oversize piston and rings.

d.
Carefully
inspect the cylinder block for small

cracks
or fractures, and for porosity.
Rust
in any
cylinder
bore may indicate a leak.

e.
Inspect all machined surfaces for scoring and

burrs.
With
a straight
edge
and feeler
gauge,
check
each
machined surface for distortion.

D1-37.
Cylinder Block Repair
If
one or more cylinder bores are rough, scored, or

worn
beyond prescribed limits, it
will
be necessary
to correct bores and fit new pistons.

If
relatively few bores require correction, it
will

not be necessary to rebore all cylinders to the same
oversize in order to maintain
engine
balance, since
all
oversize pistons are held to the same weights as

standard-size
pistons. If conditions justify replace­
ment of all pistons, however, all new pistons should
be the same nominal size.

Standard-size
service pistons are high-limit, or

maximum
diameter; therefore, they can usually be installed after a slight amount of honing has
been
done
to correct slight scoring or excessive

clearances.
This
applies
primarily
to
engines
which
have relatively low mileage. Service pistons are also furnished in .010"
[0,254
mm.] oversize. All

service
pistons are diamond bored, and selectively
fitted with piston pins; pistons are not furnished
without pins.

Caution:
Do not attempt to cut down oversize pis­

tons
to fit cylinder bores as this
will
destroy the

surface
treatment and affect the weight. The small­
est possible oversize service pistons should be used

and
the cylinder bores should be honed to size

for
proper clearance.

Before
honing or reboring cylinders, measure all new pistons with a micrometer, on an axis perpen­

dicular
to the piston pin. Select the smallest piston

for
the first fitting. The slight variation usually
found between pistons in a set may provide for
correction
in case the first piston tried is too

small.

If
wear at top of cylinder
does
not exceed .005" [0,127 mm.]
excess
diameter, or exceed .003"
[0,076 mm.] out-of-round, honing is recommended.

If
wear or out-of-round
exceeds
these
limits, the
bore should be reground with a boring bar of the

fly
cutter type, then finish-honed.

When
reboring cylinders, all crankshaft bearing caps must be in place and tightened to proper
torque to avoid distortion of bores in
final
assem­
bly.
Always be sure the crankshaft is out of the

way
of the boring cutter when boring each cylinder.
When
boring, leave the diameter .001" [0,025 mm.]

undersize,
then finish hone to obtain the required

clearance.

When
honing cylinders, use clean sharp
stones
of
proper
grade for the amount of metal to be re­
moved. Refer to instructions supplied by the hone
manufacturer.
Dull
or dirty
stones
cut unevenly

and
generate excessive heat. When using coarse

or
medium grade
stones,
leave sufficient metal so
that all
stone
marks can be removed with the fine
stones
used to finish-hone to proper clearance.

When
finish-honing, pass the hone through the entire length of cylinder at a rate of approximately 60 cycles per minute.
This
should produce the

desired
45-degree
cross hatch pattern on cylinder

walls.
A proper pattern
will
ensure maximum
ring
life and minimum oil consumption.

After
final
honing and before the piston is checked

for
fit, each cylinder bore must be washed thor­ oughly to remove all traces of abrasive, then dried completely. The dry bore should be brushed clean

with
a power-driven fibre
brush.
If all traces of

abrasive
are not removed,
rapid
wear of new pistons

and
rings
will
result.

Note:
Wipe cylinder bores with a clean white

cloth,
moistened with SAE 10 oil. Cleaning should
continue until this
test
shows no sign of
dirt.

It
is of the greatest importance that refinished

cylinder
bores be true, with .0005" [0,013 mm.]
or
less out-of-round or taper.
Each
bore must have

a
smooth surface, without
stone
or cutter
marks.
After
final
honing and cleaning, each piston must be fitted individually to the bore in which it
will

be installed. Once fitted, each piston should be
marked
with its cylinder number to assure correct

installation.
85

Dl

DAUNTLESS
V-6
ENGINE
Dl-38.
Crankshaft
Cleaning

Clean
the crankshaft thoroughly with a suitable
cleaning solvent.
Clean
drilled oil
passages
in its

journals
with a small rifle brush to remove all
sludge
or gum deposits; dry
passages
with com­
pressed air.

Dl-39.
Crankshaft
Inspection
and
Repair

If
the crankshaft has not
been
removed from the

cylinder
block for inspection, disconnect two con­ necting rods at a time from crankshaft. Inspect
the bearings and crankpin journals. While turning
crankshaft,
it is necessary to temporarily reconnect
the rods to crankshaft to avoid possibility of dam­ aging the journals through contact with uncon­
nected rods.
Inspect the crankpins visually for excessive or ir­

regular
wear, and for scoring. Use an
outside
micrometer to check crankpins for out-of-round.
Standard
crankpin
diameter is
2.0000"
[5,080
cm.].

If
crankpins are more than .0015"
[0,0381
mm.]
out-of-round, new bearings cannot be
expected
to
have satisfactory life.
If
the crankshaft has
been
removed from the
cyl­

inder
block for inspection support it on V-blocks
at its main bearing journals 1 and 4. Inspect the

main
bearing journals visually for excessive or ir­

regular
wear, and for scoring. Standard main bear­
ing
journal
diameter is 2.4995"
[6,349
cm.].
Total

indicator readings at each
journal
should not ex­
ceed .003"
[0,076
mm.].

Check
run out at all four journals and
note
high
spot
(maximum eccentricity) of each
journal.
High

spot
of each
journal
should
come
at the same
angular
location. If high
spots
do not coincide,

crankshaft
is misaligned and unsatisfactory for
service.

If
crankpin or main bearing journals are scored,
ridged, or out-of-round, the crankshaft must be replaced or reground to a standard undersize bear­
ing diameter to ensure satisfactory life of bearings. Slight roughness can be removed with a fine grit
polishing cloth thoroughly
wetted
with
engine
oil.
Burrs
can
be
honed with a fine oil
stone,
so long as
bearing clearances
will
remain within specified
limits.

Dl-40.
Crankshaft
Main
Bearings

A
crankshaft bearing consists of two halves which
are
neither alike nor interchangeable. One half is

carried
in the corresponding main bearing cap; the
other half is located
between
the crankshaft and

cylinder
block. The upper (cylinder block) half
of the bearing is grooved to supply oil to the con­ necting rod bearings, while the lower (bearing cap)

half
of the bearing is not grooved. The two bearing
halves must not be interchanged. All crankshaft
bearings
except
the thrust bearing and the
rear

main
bearing are identical. The thrust bearing (No. 2) is longer and it is flanged to take
crank­

shaft end thrust. When the bearing halves are
placed in cylinder block and bearing cap, the
ends
extend slightly beyond the parting surfaces. When
cap
bolts
are tightened, the halves are clamped
tightly in place to ensure positive seating and to
prevent turning. The
ends
of bearing halves must never be filed flush with parting surface of
crank­

case or bearing cap.

Crankshaft
bearings are the precision type which
do not require reaming to size or other fitting.
Shims
are not provided for adjustment since worn
bearings are readily replaced with new bearings of proper size. Bearings for service replacement are

furnished
in standard size and undersizes. Under no circumstances should crankshaft bearing caps
be filed to adjust for wear in old bearings.

Dl-41.
Crankshaft
Main
Bearing
Cleaning
and
Inspection

Clean
main bearing surfaces. Inspect the bearings

visually
for excessive or uneven wear, scoring, and

flaking.
Visibly worn or damaged bearings must
be replaced. It is necessary to check
radial
clear­ ance of each new or used crankshaft main bearing
before installation.
This
can be
done
by either of two methods, which are described in
Pars.
Dl-42

and
Dl-43.

a.
The desired
radial
clearance of a new bearing
is .0005" to .0021"
[0,0127
a
0,0534
mm.].
b. Replacement bearings are furnished in standard
size, and in several undersizes, including undersizes
for reground journals. If a new bearing is to be installed, try a standard size; then try each under­
size in turn until one is found that
meets
the
specified clearance limits.

Note:
Each
undersize bearing half has a number
stamped on its outer surface to indicate amount of undersize. Refer to Fig. Dl-12. 14288

FIG.
Dl-12—LOCATION
OF
UNDERSIZE
MARK
ON
BEARING
SHELL

1—
Tang

2—
Undersize
Mark
Dl-42.
Main
Bearing
Fitting,
Plastigage

Bearing
clearance can be checked by use of Plasti­
gage,
Type PG-1 (green) which has a range of
.001" to .003" [0,025 a
0,076
mm.]. Refer to

Fig.
Dl-13.

a.
Place a piece of Plastigage lengthwise along the
bottom
center of the lower bearing half, then 86

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL
Dl
A 8

j
13415

FIG.
Dl-13—USING
PLASTIGAGE
TO
MEASURE
BEARING CLEARANCE

1— Plastigage
A—Start

2—
Scale
B—Flattened

install
cap with shell and tighten
bolts
80 to 110 lb-ft. [11,1 a 15,2 kg-m.] torque.

Caution:
Do not turn crankshaft with Plastigage

in
bearing.

b.
Remove bearing cap with bearing half. The
flattened Plastigage
will
adhere either to the bear­ ing half or the
journal.
Do not remove it.
c. Using the scale printed on the Plastigage en­

velope,
measure Plastigage width at its widest
point. The number within the graduation which
most
closely corresponds to the width of Plasti­
gage
indicates the bearing clearance in thousandths
of an inch.

DI-43.
Main Bearing
Fitting,
Feeler or
Shim
Stock

A
small strip of feeler or shim stock can be used
to check main bearing clearance. The method is
simple, but care must be taken to avoid damage
to the bearing surface from excessive pressure against the strip.

a.
Cut a rectangular piece of feeler or shim stock, .001"
[.0254
mm.] thick,
i/2"
[12,70
mm.] wide, and
Vs"
[3,175 mm.] shorter than the bearing width.
Position the bearing cap to the crankshaft journal
and
cylinder block, and install two cap
bolts
loosely.

b.
Tighten alternate cap bolts, a little at a time,

until
both have
been
tightened to 35 to 45 lb-ft. [4,8 a 6,2 kg-m.] torque.
c.
Turn
the crankshaft by hand, no more than one

inch
[2,5 cm.] in either direction.

Caution:
If the crankshaft is turned too far, it
will

embed the strip in the bearing surface.
This
will
damage the bearing and also cause a false indica­tion of bearing clearance.

If
bearing clearance is correct, the strip should cause a light to heavy drag, or resistance to rotation.
If
there is little or no drag, clearance is too great;

if
the crankshaft cannot be turned, clearance is
insufficient. In either case, a different main bear­ ing must be
selected
to obtain proper clearance.

d.
Repeat
steps
a, b, and c, as necessary, to
select

proper main bearing size. After a bearing has
been

selected, remove the
test
strip from bearing on
crankshaft
journal surface; wipe both surfaces care­

fully,
and apply clean
engine
oil to both surfaces. Position the bearing cap to the crankshaft journal

and
cylinder block, and install two cap
bolts
loosely.

Tighten
alternate cap bolts, a little at a time, to

final
specified torque of 80 to 110 lb-ft. [11,1 a 15,2 kg-m.]. The crankshaft should now rotate
freely.

Dl-44.
Piston
and
Connecting
Rod
Disassembly

a.
Remove two compression rings with a piston
ring
expander. To remove oil ring, remove the two

rails
and spacer-expander, which are separate
pieces

in
each piston third
groove.

b.
From
Tool Set W-338 use support base J-6047-1
with collar J-6047-5 and driver J-6047-4 with an
arbor
press to press piston pin from piston and con­
necting rod. Mount support base and collar in press. Set driver in position and press out pin. Refer to

Fig.
Dl-14.
FIG.
Dl-14—PISTON
PIN
REMOVAL

1—
Arbor
Press

2—
Driver

3—
Piston
and Rod Assembly
4—
Collar
•
5—Support Base Dl-45.
Piston
and
Connecting
Rod
Cleaning
and Inspection

a.
Clean
carbon from piston surfaces and under­
side of piston heads, and remove all pistons rings.
Clean
carbon from ring
grooves
with a suitable tool.
Remove any gum or varnish from piston skirts with a suitable solvent.

b.
Carefully examine pistons for rough or scored
bearing surfaces, cracks in
skirt
or head, cracked

or
broken ring lands, chipping and uneven wear 87

Pi

DAUNTLESS
¥-6
ENGINE
which
would cause rings to seat improperly or have
excessive clearance in
ring
grooves. Damaged or
faulty
pistons should be replaced,
c.
Inspect bearing surfaces of piston pins and check

for
wear by measuring worn and unworn surfaces

with
a micrometer. Rough or worn pins should be
replaced.
Test fit the piston pins in piston
bosses.
Occasionally,
a pin
will
be tight due to gum or

varnish
deposits.
This
may be corrected by remov­

ing
the deposit with a suitable solvent. If piston
bosses
are worn out-of-round or oversize, the piston

and
pin assembly must be replaced. Oversize pins
are
not
practical,
since the pin must be a press fit
in
the connecting rod bore. Piston pins must fit the
piston with an easy finger push at
70°F.
[21°C.].

They
should have .0004" to .0007"
[0,0178
a
0,0102
mm.] clearance.

Dl-46.
Piston Fitting

If
cylinder bores are rebored or heavily honed,
new and possibly oversize diameter pistons must be
installed.
A new piston must be fitted to its cylinder

bore.
A satisfactory method of fitting pistons is as
follows.

a.
Expand
a
telescope
gauge
to fit the cylinder bore at right angles to the piston pin and
between
1
Vi"
to 2" [3,7 a 5,1 cm.] from the top.

b.
Measure diameter of the piston to be fitted, as
shown in
Fig.
Dl-15. The piston must be measured

at
right angles to the piston pin, W [6,3 mm.] below the oil
ring
groove. The piston must be be-
FIG.
Dl-15—MEASURING
PISTON

1—90°
tween .001" and .0015" [0,025 a
0,038
mm.]

smaller
than the cylinder bore.

Note:
Both cylinder block and piston must be at

very
nearly the same temperature when measure­
ments are made or
errors
due to expansion
will
occur.
A difference of 10°F.
[5,6°C]
between
parts
is sufficient to produce a variation of .0009"
[0,0023
mm.].

The
pistons are cam-ground, which means that the
diameter at a right angle to the piston pin is
greater
than the diameter
parallel
to the piston

pin.
When a piston is checked for size, it must be
measured
with a micrometer applied to the
skirt

along a line
perpendicular
to axis of the piston pin.

Dl-47.
Piston Ring Fitting

When
new piston rings are to be installed without

reboring
cylinders,
the glazed cylinder walls should
be slightly dulled. However, cylinder bore diameter
should
not increase more than necessary.
Cylinder

walls
should be honed with the finest grade of
stone
to remove any glaze.
New compression rings must be checked for clear­ ance in piston
grooves
and for gap in cylinder bores;
however, the flexible oil rings are not checked for gap. The cylinder bores and piston
grooves
must
be clean, dry, and free of carbon and
burrs.

With
rings installed on piston, check clearance in
grooves
by inserting feeler
gauge
between
each
ring

and
its lower
land.
Any
ring
groove
wear
will
form

a
step
at inner portion of the lower
land.
If the
piston
grooves
have worn enough that relatively

high
steps
exist on the lower lands, the piston
should
be replaced because the
steps
will
interfere

with
proper operation of new rings and the
ring
clearances
will
be excessive. Piston rings are not

furnished
in oversize widths to compensate for
ring
groove
wear.

When
fitting new rings to new pistons, the side

clearance
of the compression rings should be .002" to .0035"
[0,051
a
0,089
mm.] for number one (1)

ring,
.003" to .005" [0,076 a 0,127 mm.] for number
two (2)
ring,
and side clearance of the oil
ring
should
be .0015" to .0085" [0,038 a
0,220
mm.].

To
check the end gap of a compression
ring,
place

it
in the cylinder in which it
will
be used, square

it
in the bore by tapping with the lower end of
a
piston, then measure the gap with a feeler
gauge.

A
compression
ring
should not have
less
than .015"
[0,381
mm.] gap when placed in cylinder

bore.
If gap is
less
than specified value, file the
end of the
ring
carefully with a fine file to obtain

proper
gap.

Dl-48.
Piston and Connecting Rod Assembly

Note:
A connecting rod can spring out of alignment

in
shipping or handling. Always check a new con­
necting rod for misalignment before installing pis­
ton and pin.

a.
If a new connecting rod is to be installed, check
its alignment with an accurate rod alignment fix­

ture.

b.
If the piston and connecting rod assembly is
to be installed in the left cylinder bank, it must be assembled as shown in
Fig.
Dl-16. If the piston and
connecting rod assembly is to be installed in the
right
cylinder bank, it must be assembled as shown
in
Fig. Dl-17.
Note
that
these
two assemblies are

mirror-images
of each other.

c.
Lubricate
piston pin to avoid damage when

pressing
through the connecting rod.

d.
To install piston pin in piston and connecting

rod,
use
Tool
Set W-338.
Install
collar J-6047-5,
spring
J-6047-3, and pilot J-6047-20 into the base

support
J-6047-1 and place in
arbor
press. Using

driver
J-6047-4 press piston pin into piston and 88

DAUNTLESS
V-6
ENGINE

Note:
The rib on
edge
of cap and the conical
boss

on web of connecting rod must be toward
rear
of
engine
in all connecting rod assemblies of left
cyl­

inder
bank and toward front of
engine
in all con­necting rod assemblies of right cylinder bank.

Dl-50.
Oil
Pump Intake
and
Screen Cleaning

a.
Pry screen from housing and examine for clog­
ging due to deposit of sludge or other foreign

material.

b.
Clean
the screen and housing thoroughly in sol­
vent; dry with compressed air.

c.
Install
screen in housing.

Dl-51.
Oil Pan Cleaning and Inspection

Inspect
the oil pan for corrosion, dents, leaks, and
other damage. Inspect its mounting flange carefully
for damage or distortion to be certain that it
will
give
a
good
seal.

Dl-52.
Flywheel Cleaning
and
Inspection

Clean
the flywheel with suitable cleaning solvent;

dry
with compressed air. Inspect clutch face for

burned
or scuffed condition and for rivet grooves.
Inspection
for run out or improper mounting is de­

scribed
in installation procedure.
Inspect
teeth
of the flywheel
ring
gear for
burrs,

nicks,
and minor distortion. If necessary and pos­
sible, use a small emery wheel to remove
burrs
and
reshape teeth. If gear
teeth
are broken,
cracked,

seriously
burred
or deformed, the
ring
gear must be replaced.

Dl-53.
Ring Gear Replacement

a.
Drill
a
hole
between
two
ring
gear teeth; then

split
the gear with a cold chisel. Be careful not to
damage
ring
gear shoulder or seat surfaces of fly­
wheel.

b.
Polish several
spots
on the new
ring
gear to be

installed.
With
a hot plate or slowly moving torch,
heat the new
ring
gear until polished
spots
become

blue, about
600°F.
[312°C.].

Caution:
Do not heat the
ring
gear to a temperature
greater than
800°F.
[424°C.].
Excessive heat
will

destroy heat treatment given to
ring
gear during
manufacture.

c.
Quickly
install
ring
gear on flywheel. Chamfered

edge
of
ring
gear must be toward
ring
gear shoulder
of flywheel. Be certain that
ring
gear is seated prop­

erly.
Allow
ring
gear to cool slowly, so that it
will

be held tightly in place.

Dl-54.
Flywheel Housing Cleaning and Inspection

Both
flywheel and clutch are enclosed by a fly­
wheel housing. Its front surface is bolted to the
engine
cylinder block, and its
rear
surface acts as

front
support to the transmission.
Clean
the fly­ wheel housing with a suitable cleaning solvent; dry
with
compressed air. Inspect front and
rear
surfaces
for distortion and improper alignment with each
other;
these
planes must be
parallel
to assure
proper
alignment
between
engine
and transmission.
Dl-55.
Camshaft Cleaning
and
Inspection

Clean
both camshaft and camshaft bearing surfaces

with
a suitable cleaning solvent; dry with com­
pressed air.

Note:
The steel-backed babbitt-lined camshaft
bearings are pressed into the crankcase.
From
front
to
rear,
each bearing is .030" [0,76 mm.] smaller
in
diameter than the preceding bearing.
From
front
to
rear,
each camshaft
journal
is correspondingly
smaller
in diameter.

The
camshaft bearings must be line reamed to

proper
diameter after being pressed into crankcase.
Since
this operation requires special reaming equip­
ment, the original bearings should be retained un­
less
they are severly damaged. Slightly scored cam­
shaft bearings are satisfactory if the surfaces of camshaft journals are polished, bearings are
polished to remove
burrs,
and
radial
clearance

between
camshaft and bearings is within .0015"
to .004" [0,038 a 0,102 mm.].

Dl-56.
Valve Lifter
and
Push
Rod
Cleaning and Inspection
a.
Examine the cam contact surface at lower end of each valve lifter body. If surface is excessively

worn,
galled, or otherwise damaged, discard the
valve lifter. Also examine the mating camshaft
lobe
for excessive wear or damage.

b.
Disassemble one or two valve lifters, as de­

scribed
below, and inspect them for
dirt
or
varnish.
If
they are dirty or have a varnish deposit, clean

and
inspect all twelve valve lifters. Otherwise,
service
only
those
valve lifters which do not operate

properly.

c.
To disassemble each valve lifter, depress the
push
rod seat with a push rod, and remove the
plunger retainer from the valve lifter body with

a
retainer remover. Remove push rod seat and
plunger from valve lifter body. If plunger sticks
in
valve lifter body, place body in large end of

a
plunger remover tool, with plunger downward.
While
holding lifter with thumb, rap the open end
of remover against a block of wood with just enough force to jar the plunger from body. Refer to
Figs.
Dl-20, Dl-22 and Dl-23.

d.
Drain
oil from valve lifter and remove the check
valve retainer,
ball,
valve spring, and plunger
spring.

e. Keep all parts of each valve lifter separated

during
part cleaning and inspection. The valve

lifter
body and plunger are selectively fitted to each other and must not be interchanged with parts
of other valve lifters.
f. Rinse all valve lifter parts in kerosene to remove as much oil as possible.
This
will
reduce contamina­
tion of the cleaning solvent. Immerse all parts in cleaning solvent for approximately one hour. The
time required
will
depend on varnish
deposits
and
effectiveness
of the solvent. After the varnish has
dissolved or has
softened
sufficiently to permit re­

moval
by wiping, allow parts to
drain.
Varnish
can
then be cleaned from the valve lifter body
with
a
brush.
Rinse the parts in kerosene to dissolve 90

Di

DAUNTLESS
V-6
ENGINE

12721

FIG.
D1-22—REMOVAL
AND
INSTALLATION
OF
VALVE
LIFTER
RETAINER
RING

A—Removal'
1—
Push
Rod

2—
Tool
3-

B-
-Retainer

-Installation

T)
0
© ©
6
FIG.
D1-23—HYDRAULIC
VALVE
LIFTER

1—
Body

2—
Spring

3—
Ball
Retainer

4—
Ball
5— -Plunger
6—
Push
Rod
Seat
7—
-Retainer

rinse
and
install
the
check valve
ball,
check valve

spring,
check valve retainer, plunger spring,
and
valve lifter body over
the
plunger. Rinse push
rod

seat and retainer ring in kerosene. Place
these
parts

in
end of
body and depress with
a
suitable tool
to

cause retainer
to
engage
groove
in
valve lifter body.

o.
Wrap
the
valve lifter
in
clean paper,
or
other­
wise protect
it
from
dirt,
during cleaning
and in­

spection
of the
other valve lifters.

Dl-57.
Hydraulic Valve
Lifter
Leak-down
Test

Check
leak-down rate
of
hydraulic valve lifters

with
valve lifter pliers W-324
or
equivalent.
Im­
merse
the
valve lifter
in
kerosene
and
grasp
the

valve lifter with
the
pliers,
as
shown
in
Fig. Dl-24, so that
the
push rod
of the
pliers
engages
the
push

rod
socket
of
the lifter. Squeeze and hold
the
pliers,

checking
the
time required
for
leak-down.
Leak-

down should take
between
12 and 60
seconds.
Check
a
doubtful valve lifter three
or
four times.

Replace
valve lifters that
do not
have
a
proper
leakdown rate.
FIG.
Dl-24—VALVE
LIFTER
TEST

Dl-58.
Rocker
Arm
Disassembly

This
engine
has two
rocker arm assemblies, each of which
is
associated with
one of its two
cylinder

banks.
Each
rocker arm assembly
is
disassembled as follows:

a.
Remove cotter pin, flat washer, spring retaining

ring,
and one
rocker
arm
from each
end of the

rocker
arm shaft.

b.
Withdraw
two
bolts
from outer shaft supports

and
rocker arm shaft. Remove outer supports,
two
rocker
arms, two spacer springs, and
two
remaining

rocker
arms from shaft. Withdraw bolt from center
support
and
remove support from shaft.

Dl-59.
Rocker
Arm Cleaning and
Inspection

a.
With
a
wire brush and suitable cleaning solvent,

clean
any
sludge
or
dirt
from hollow core
and

oil
ports
of the
rocker
arm
shaft, from bores
of
shaft supports, and from
oil
passage
in
each rocker

arm.
Dry
these
parts with compressed
air.
Clean
all
other parts with cleaning solvent and dry with
compressed
air.

b.
Inspect
the
rocker
arm
shaft
for
scoring
or

abrasion
at the
rocker arm bearing areas and, with

a
surface plate, check
for
bent
or
distorted condi­
tion. Inspect
the
rocker arms
for
excessive wear,

scoring,
or
abrasion
of
bearing surfaces.
Check
for

loose
or
damaged valve stem
or
push
rod
inserts.
Inspect
the
spacer springs
for
breaks, deformity,

and
loss
of
tension. Replace
any
visibly worn
or

damaged parts. Inspect
the
mounting
bolts
for

damage.
Repair
damaged threads
or
replace
as
necessary.

c.
Measure rocker
arm
shaft diameter
and
bore
diameters
of
rocker arms.
This
clearance should be .0017"
to
.0032"
[0,0432
a
0,0812
mm.]. If
necessary, replace worn rocker arms, shaft,
or
both.

Dl-60.
Rocker
Arm Assembly

Note:
All three shaft supports
of
each rocker arm
assembly are identical and interchangeable. In
the

description
to
follow, "center"
and
"outer" refer only
to
their position
on the
shaft.

Caution:
There
are two
different
types
of
rocker

arms,
three
of
each type,
in
each rocker arm shaft
assembly. They
are not
interchangeable. One face
of each rocker arm
has a
notch; when installed
on

the shaft, this notched face must touch
a
shaft support.
92

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

Dl Caution:
Oil ports of the rocker arm shaft must
coincide with oil return passages of the rocker

arms.
If they do not,
engine
oil has no return path

from
the cylinder head to the crankcase; in that
case,
engine
oil flows down the valve
stems
and

burns
in the cylinders.
There
is a notch at one end of each rocker arm shaft. When rocker arms
are
properly installed on the shaft, this notch
will

be at front of right rocker arm shaft and at
rear
of left rocker arm shaft. Refer to
Figs.
Dl-25 and

Dl-26.

a.
Position center support on rocker arm shaft;

insert
one shaft assembly attaching bolt through
support and shaft to hold support in position.

b.
Install
center
pair
of rocker arms with notched
faces touching support.
Install
front and
rear
spacer
FIG.
Dl-25—FRONT
OF RIGHT

ROCKER
ARM SHAFT
1—Alignment Notch

FIG.
Dl-26—REAR OF
LEFT
ROCKER
ARM SHAFT 2—Alignment Notch springs and one rocker arm each of front and
rear

rocker
arm pairs on shaft. Be certain that notched
faces of rocker arms are outward.
Install
outer shaft supports on shaft; compress spacer springs
to position supports. Insert one shaft assembly bolt
through each support and shaft to hold supports in
position.

c.
Install
remaining rocker arms of front and
rear

pairs,
each with notched face touching shaft sup­

port.
Install
a spring retaining ring and flat washer at each end of shaft; secure each of
these
with a
new cotter pin.

D1 -61.
Valve Removal

a.
Place cylinder head on clean, smooth surface.

b.
Remove each valve assembly from cylinder
head as follows. Using suitable spring compressor, compress valve spring and remove two valve re­

tainers
from valve stem. Release spring compressor,

and
remove spring retainer and valve spring from
valve stem. Refer to Fig. Dl-27.

Note:
Valve retainers are copper-colored for identi­
fication purposes only.

c.
Withdraw valve from
bottom
of cylinder head.
Valves
should be identified so they can be installed

in
original location.

D1-62.
Cylinder
Head and Valve Cleaning
and
Inspection

a.
Remove carbon from combustion chamber of
cylinder
heads, using care to avoid scratching the head of valve seat surfaces. A
soft
wire brush is
suitable for this purpose.

b.
Clean
carbon and gum
deposits
from valve guide
bores with a standard-size valve guide reamer.

Refer
to Fig. Dl-28.

c.
Clean
valves with a wire
brush.
Inspect valve
faces and
seats
for pits, burned
spots
or other evi­ dence of poor seating.
FIG.
D1 -2 7—REMOVING
VALVE
RETAINERS
1—
Valve
Stem 3—Valve Spring Retainer

2—
Valve
Lock
4—Valve Spring
93

Dl

DAUNTLESS
V-6
ENGINE

FIG.
D1-28—CLEANING
OR
ENLARGING
VALVE
GUIDE

1—Reamer
d.
Measure clearance of each valve stem in cor­
responding valve guide. For intake valves, this
clearance
should be .0012" to .0032" [0,0305 a

0,0813
mm.]. For exhaust valves, this clearance should be .0015" to .0035"
[0,0381
a
0,0889
mm.]
at top of guide and .002" to .004"
[0,051
a 0,102 mm.] at bottom of guide. If this clearance is exces­
sive, valve guides must be reamed with .004" [0,102 mm.] oversized reamer J-5830-1 and valves

replaced
by new valves with oversize stems.

Dl-63.
Cylinder
Head
and Valve
Repair
a.
If a valve stem has excessive clearance in its
guide, the guide must be reamed .004" [0,102 mm.]
oversize. Valves are available with oversize stems
to fit this valve guide diameter.

b.
Grind
valve faces or replace valves if necessary.

Valve
faces must be ground at an angle of 45 degrees. If a valve head must be ground to a
knife
edge
to obtain a true face, the valve should
be replaced.

c.
If necessary, grind valve seats at an angle of 45 degrees.
Grinding
a valve seat decreases valve
spring
pressure and increases the width of the seat.

The
nominal width of the valve seat is
[
1,59
mm.].
If a valve seat is wider than %" [1,98 mm.]
after grinding, it should be narrowed to specified

width
by the use of 20-degree and 70-degree stones.
Improper
operation of a hydraulic valve lifter may

result
if valve and seat are refinished to the extent
that the valve stem is raised more than .050" [1,27 mm.] above normal height. In this case, it
is necessary to grind off the end of the valve stetti or replace parts.

Note:
The normal height of the valve stem above
the valve spring seat surface of the head is
1.925"
[4,889 cm.].

d.
Lightly
lap the valves into seats with fine grind­
ing compound. The refacing and reseating should
leave the refinished surfaces smooth and true so that a minimum of lapping
will
be required. Ex­
cessive lapping
will
groove the valve face and pre­
vent
good
valve seating.
e. Test valve seats for concentricity with guides,
and
for proper valve seating. Coat a small segment
of the valve face lightly with Prussian blue pig­ ment.. Insert the valve stem into its guide and

turn
the valve face against the seat. If the valve seat is concentric with the valve guide, a
mark

will
be made all around the seat. If the seat is not concentric with the guide, a
mark
will
be made
on only one side of the seat.

Clean
all pigment from both valve and seat. .Next,
coat a small segment of the valve seat lightly with

Prussian
blue pigment. Again insert the valve stem into its guide and rotate the valve face against the
seat. If the valve face is concentric with the valve
stem, and if the valve is seating all the way around,
pigment
will
coat the valve face with a uniform
band
around its entire perimeter. Both of
these

tests
are necessary to prove that proper valve seat­
ing is obtained.
f. Inspect the valve springs visually for corrosion,

breaks,
and distortion.
With
a valve spring tester
check
each valve spring for proper tension. When

a
valve spring is compressed to a length of
1.640"
[4,166 cm.] (closed-valve condition), it should
have a tension of 64 lb. [29,03 kg.]. When a valve
spring
is compressed to a length of
1.260"
[3,200
cm.] (open-valve condition), it should have ten­ sion of 168 lb. [76,205 kg.]. Replace any valve
spring
which is visibly damaged or
does
not
meet

tension specifications.

Dl-64.
Valve Installation

Lubricate
valve stems with engine oil.
Install
valves, valve springs, spring retainers, and valve

retainers
on the cylinder head. Use the same equipment and reverse procedure used for removal.

Install
valve springs with closely wound coils to­

ward
the cylinder head. Refer to Fig. Dl-29.
FIG.
Dl-29—VALVE
SPRING

1—
Spring

2—
Close
Wound
Coils
Toward
Head
94